joe biden campaigned earlier in florida. >>> busy 405 was shut down for road work. motorists have been asked to stay off the roadways in that area during the 53-hour closing which began today. now back to "caught on camera." >>> so far we've shown you stories of brave rescues of individuals trapped in frightening situations but what happens when a natural disaster strikes a major american city, devastating whole neighborhoods. it will take heroic efforts by rescuers to save as many trapped victims as they can. a mall parking deck collapses. >> we have one man that is under a parking structure, a crush injury. >> and a mile away at the very same moment, an apartment complex caves in. >> i remember breaking down and crying. i wasn't ready to die. >> people trapped everywhere. >> we've been hit with a major earthquake. >> it is 4:31 a.m., january 17th, 1994. centered in the north ridge section of los angeles, california, 20 miles north of downtown, it all happened so fast, in seven terrifying seconds, nature unleashes its fury. >> the first thing i heard was a loud exp